Electrode support



Patented June. 21, 1938 2,121,597 ELECTRODE sm'ro'n'r Otto Karl, Berlin,Germany, asslgnor to Siemens & Halske Aktiengesellschaft,

Germany, a corporation of Gernear Berlin, many Siemensatadt,

Application November 6, 1937, Serlal No. 173,263 In Germany November 30,1938 8 Claims. (Cl. 250- 27.5)

The invention" relates to electrodes and their supports and especiallyto grid and grid suppor s.

An object of the invention is to provide a sturdy and easily formedelectrode and electrode support.

The invention sheetmetal, which may be connected in parallel so as toform one composite electrode. The invention contemplates directly fusingsuch an electrode, for example a grid, into one or'more plates or ringsof glass or of vitreous material which will thus support the electrode.The. supporting plates can be provided at either one or at both ends ofthe electrode or electrodes and may be attached in any suitable mannerto the vessel. The supporting plates can be circular, ring shaped, orcornered. as desired, depending upon the construction of the electrode.

The application of the newmethod is especially advantageous if the sheetmetal to be supported by the plates is thin. The invention is of specialimportance if a great number of sheet metal electrodes must be supportedin such a m'anner that the distances between the individual electrodeswill be exactly equal to definite predetermined values. This lattercondition is present inthe case of electronic amplifiers and similartubes. Up to the present time, the mounting of the numerous sheet metalelectrodes in tubes of 'this type has been quite intricate from atechnical standpoint. According to the invention,-however, thework-involved will be greatly simplified. An electrode system assembledby the invention offers the advantage thatit will be of more stableconstruction.

Other advantages ,will be apparent from the following description anddrawing, in which:

Figure 1 is a perspective view of a preferred modification;

Fig. 2 is a modification;

Figs. 3 and 4 are perspective views of a still perspective view of astill further further modification in an initial and intermediate formwhile; I

Fig. 5 is a cross sectional view of article and apparatus for obtainingthe article in Fig. 4'

from that in Fig. 3;

Fig. 6 is a side elevation of the finalform;

Fig. 7 is a perspective view of a still further modification of theinvention; and Fig. 8 is a side elevationalview with parts bro ken awayto illustrates. preferred embodiment of complete electrode structure.

particularly concerns one or a plurality of individual electrodes,preferably of- The general principle involved in constructing anelectrode according to the invention is illustrated by Fig. 1. The twohalves 3 and I of an electrode of sheet metal are fused into thesupporting plates l and 2 of glass which, in this 5 particular case, arering shaped. The other elec: trodes can project into the opening 5 intothe inner space surrounded by the two sheets 3 and 4, although they maybe supported by parts located outside of this space. These other eiec'1o trodes may, of course, be fused into the supporting plates of glass Iand 2, Just mentioned.

Fig. 2 discloses a flat type of grid. The parallel elements 1 are strapsof thin sheet metal and are fused into the glass disc 6. A duplil5 catedisc may be providedat the other end of the electrode. I Y

A cylindrical grid-like electrode according to the invention, isillustrated in Figs. 3, 4, 5 and 6. As indicated in Fig. 3, a cylinderof sheet metal 20' is provided with slits 9 that run parallel to theaxisof the cylinder so that there are formed a number of strips Ill whichhang downward from the border 8 of the sheet metal cylinders. The sheetmetal strips are then preferably bent around 25 axes parallel to theaxis of the cylinderuntil' they form with the radius a certain angle oruntil they have the direction of the radius of the cylinder. Thisconstruction is'illustrated inFlg.

4. The grid;is fastened in a suitable manner above a mold l2 as shown inFig. 5. This mold is preferably of graphite and has the shape of a ringprovided with a groove l3. The groove I3 is then filled with moltenglass ll so that there will be formed a solid glass frame supportas ingthe strips constituting the grid. The same procedure should be followedif. it should be desired to provide the other side of the electrode witha supporting glass plateor glass frame. The non-slitted border 8 of thecylinder can be cut 40 ofl. and the electrodeturned upside down so thatthe process of fusion can be repeatedfor this end of the electrode. Inthis manner is obtained an electrode having the shape represented inFig. 6. A portion of the non-slitted part may (l5 be left forelectrically connecting the parts or this may be accomplished by joiningthe parts with a wire or strap ofconducting material to all or to groupsof the straps as desired. It is: equally possible to use at thebeginning individ- 50 ual straps of sheet metal held at one end inproper position by means of a rig of simple construction so that theycan be fused into glass at one end and then turned upside down and-.provided with a glass ring at the other end. '65 I The electrode,however, might be finished at the free end by other means than that ofglass because of the stable position maintained by the fused glass atthe other end.

In the case of electrodes subject to high heat under normal operatingconditions, it may be desirable to protect the fused regions in theirneighborhood by establishing a heat conductive connection between thesheet metal of the electrode and the parts that the developed heat byradiation because only a small fraction of that heat will then reachthese fused regions.

Fig. 7 shows how great a number of sheet metal electrodes l4v can besupported by means of glass plate i5. Electrode systems of this kind arefound, for example, in electronic amplifiers. The electrode plates inFig. '7 could, of course, be arranged concentrically and. fused into aring of glass, if desired. It is especially advantageous to use thesupport- 'ing plates of glass at the same time for sealing an opening inthe wall of the vessel. An example of this is given in Fig. 8. Two glassplates it and ill support an anode i8, a grid l9, and a cathode 2B. Thelead of the anode is designated by 2|, that of the grid by 22 and thoseof the cathode by 23 and 2%. a

In those cases where there is any danger of short circuits betweenelectrodes having difierent potentials due to a condensation of some ofthe metal vapor contained into the tube on the supporting parts, it maybe advisable to roughen the surface of the glass at these parts or tocover it with an oxide layer such as aluminum oxide.

It is apparent that many modifications may be made in the preferredembodiments illustrated without departing from the spirit of theinvention. Accordingly, only such limitations should be put on thefollowing claims as are necessitated by the prior art.

, I claim as my invention:

1. An electrodeand support therefor for an electrical discharge devicecomprising a plurality will readily dissipate ammo? of parallel sheetsof metal and insulating material iused thereto at the ends.

2. The method of constructing an electrode structure which comprisesslitting one end of sheet material into parallel straps and fusinginsulating material to the ends of said straps.

3. The method of constructing an electrode structure which comprisesslitting one end of sheet material into parallel straps and fusinginsulating material to the ends of said straps, cutting off the partabove said straps and fusing insulating material in place thereof.

4. The method of constructing an electrode structure which comprisesforming a metal sheet material into a cylinder, slitting one end intoparallel straps, bending said straps to the desired angle and fusinginsulating material to the ends of said straps.

5. The method of constructing an electrode structure which comprisesforming a metal sheet material into a cylinder, slitting one end intoparallel straps, bending said straps to the desired angle and fusinginsulating material to the ends of said straps, cutting oi? the partabove said straps and fusing insulating material in place thereof.

6. The method of constructing electrode structure which comprisesslitting one end of sheet material into parallel straps, bending saidstraps to the desired angle and fusing insulating material to the endsof said straps.

'7. The method of constructing electrode structure which comprisesaligning metal straps into parallel relation, bringing the ends of thestraps and molten insulating material together in a mold .of the desiredshape'and fusing the straps and material together.

8. An' electrode and support therefor for an electrical discharge devicecomprising a plurality of parallel sheets of metal and insulatingmaterial fused thereto at the ends, said insulating materialbeing coatedaround said metal with aluminum oxide.

O'ITO KARL.

